Climate Change Can’t Be Undone?

Joe Nocera makes the claim (NYT) that reducing emissions from Chinese coal plants “would do far more to help reverse climate change” than preventing the construction of the Keystone pipeline. Joe Romm fumes:

The fact is that, as RealClimate has explained, we would need “an immediate cut of around 60 to 70% globally and continued further cuts over time” merely to stabilize atmospheric concentrations of CO2 – and that would still leave us with a radiative imbalance that would lead to “an additional 0.3 to 0.8ºC warming over the 21st Century.” And that assumes no major carbon cycle feedbacks kick in, which seems highly unlikely.

He goes on to insist that this “doesn’t mean climate change is unstoppable — only that we are stuck with whatever climate change we cause before we get desperate and go all WWII on emissions.”